Add support for Array API in NamedArray

.github/workflows/array-api-tests.yml

@@ -0,0 +1,46 @@
+name: NamedArray._array_api
+
+on: [push, pull_request]
+
+env:
+  PYTEST_ARGS: "-v -rxXfE --ci --hypothesis-disable-deadline --max-examples 5"
+  API_VERSIONS: "2023.12"
+
+jobs:
+  array-api-tests:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ['3.12']
+        exclude:
+          - python-version: '3.8'
+
+    steps:
+    - name: Checkout xarray
+      uses: actions/checkout@v4
+      with:
+        path: xarray
+    - name: Checkout array-api-tests
+      uses: actions/checkout@v4
+      with:
+        repository: data-apis/array-api-tests
+        submodules: 'true'
+        path: array-api-tests
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v5
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Install Dependencies
+      run: |
+        python -m pip install --upgrade pip
+        python -m pip install ${GITHUB_WORKSPACE}/xarray
+        python -m pip install -r ${GITHUB_WORKSPACE}/array-api-tests/requirements.txt
+        python -m pip install hypothesis
+        python -m pip install array-api-strict
+        python -m pip install array-api-compat
+    - name: Run the array API testsuite
+      env:
+        ARRAY_API_TESTS_MODULE: xarray.namedarray._array_api
+      run: |
+        cd ${GITHUB_WORKSPACE}/array-api-tests
+        pytest array_api_tests/ --skips-file ${GITHUB_WORKSPACE}/xarray/xarray/tests/namedarray_array_api_skips.txt ${PYTEST_ARGS}

xarray/core/variable.py

@@ -1653,6 +1653,11 @@ def reduce(  # type: ignore[override]
             Array with summarized data and the indicated dimension(s)
             removed.
         """
+        if dim is None:
+            from xarray.namedarray._typing import _default
+
+            dim = _default
+
         keep_attrs_ = (
             _get_keep_attrs(default=False) if keep_attrs is None else keep_attrs
         )